AS1334

650mA, Ultra low Ripple Step Down DC/DC Converter

www.austriamicrosystems.com/DC-DC_Step-Down/AS1334

Revision 1.09

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Datasheet

1 General Description

The AS1334 is a step-down DC-DC converter designed to power

portable applications from a single Li-Ion battery. The device also

achieves high-performance in mobile phones and other applications

requiring low dropout voltage.

The AS1334 operates from an input voltage range of 2.7 to 5.5V

while providing output voltages of 1.2, 1.5, 1.8, 2.5, 3.0 and 3.3V.

Fixed-frequency PWM operation minimizes RF interference.

Shutdown function turns the device off and reduces battery

consumption to 0.01µA (typ).

The AS1334 is available in a TDFN(3x3) 8-pin package. A high

switching frequency (2 MHz) allows use of tiny surface-mount

components. Only three small external surface-mount components,

an inductor and two ceramic capacitors are required.

Figure 1. AS1334 - Typical Application Circuit

2 Key Features

Output Voltage Ripple: 2mV

PWM Switching Frequency: 2MHz

Single Lithium-Ion Cell Operation

Output Voltage Range: 1.2V to 3.4V

(available in 100mV steps, see Ordering Information on page 17)

Fixed Output Voltages:

- 1.2V, 1.5V, 1.8V, 2.5V, 3.0V, 3.3V

Maximum Load Capability of 650mA

97% High Efficiency, 94% Average Efficiency

Current Overload Protection

Thermal Overload Protection

Power-OK

Soft Start

Low Dropout Voltage (140 m

Ω Typ PFET)

TDFN(3x3) 8-pin

3 Applications

The AS1334 is an ideal solution to supply noise sensitive

applications as cellular phones, hand-held radios, RF PC cards,

battery powered RF devices, RFID chipsets, A/D Converter, Sensors

and OpAmps.

AS1334

PGND

SGND

EN

PVIN

VDD

SW

FB

10 µF

3.3 µH

10 µF

ON

OFF

POK